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sys/netinet6/in6_src.c
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1 /* $FreeBSD: releng/6.3/sys/netinet6/in6_src.c 172047 2007-09-04 22:40:40Z alfred $ */ 2 /* $KAME: in6_src.c,v 1.132 2003/08/26 04:42:27 keiichi Exp $ */ 3 4 /*- 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /*- 34 * Copyright (c) 1982, 1986, 1991, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 4. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include "opt_inet.h" 65 #include "opt_inet6.h" 66 67 #include <sys/param.h> 68 #include <sys/systm.h> 69 #include <sys/malloc.h> 70 #include <sys/mbuf.h> 71 #include <sys/protosw.h> 72 #include <sys/socket.h> 73 #include <sys/socketvar.h> 74 #include <sys/sockio.h> 75 #include <sys/sysctl.h> 76 #include <sys/errno.h> 77 #include <sys/time.h> 78 #include <sys/kernel.h> 79 #include <sys/lock.h> 80 #include <sys/sx.h> 81 82 #include <net/if.h> 83 #include <net/route.h> 84 85 #include <netinet/in.h> 86 #include <netinet/in_var.h> 87 #include <netinet/in_systm.h> 88 #include <netinet/ip.h> 89 #include <netinet/in_pcb.h> 90 #include <netinet6/in6_var.h> 91 #include <netinet/ip6.h> 92 #include <netinet6/in6_pcb.h> 93 #include <netinet6/ip6_var.h> 94 #include <netinet6/scope6_var.h> 95 #include <netinet6/nd6.h> 96 97 #include <net/net_osdep.h> 98 99 static struct mtx addrsel_lock; 100 #define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF) 101 #define ADDRSEL_LOCK() mtx_lock(&addrsel_lock) 102 #define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock) 103 #define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED) 104 105 static struct sx addrsel_sxlock; 106 #define ADDRSEL_SXLOCK_INIT() sx_init(&addrsel_sxlock, "addrsel_sxlock") 107 #define ADDRSEL_SLOCK() sx_slock(&addrsel_sxlock) 108 #define ADDRSEL_SUNLOCK() sx_sunlock(&addrsel_sxlock) 109 #define ADDRSEL_XLOCK() sx_xlock(&addrsel_sxlock) 110 #define ADDRSEL_XUNLOCK() sx_xunlock(&addrsel_sxlock) 111 112 #define ADDR_LABEL_NOTAPP (-1) 113 struct in6_addrpolicy defaultaddrpolicy; 114 115 int ip6_prefer_tempaddr = 0; 116 117 static int selectroute __P((struct sockaddr_in6 *, struct ip6_pktopts *, 118 struct ip6_moptions *, struct route_in6 *, struct ifnet **, 119 struct rtentry **, int, int)); 120 static int in6_selectif __P((struct sockaddr_in6 *, struct ip6_pktopts *, 121 struct ip6_moptions *, struct route_in6 *ro, struct ifnet **)); 122 123 static struct in6_addrpolicy *lookup_addrsel_policy __P((struct sockaddr_in6 *)); 124 125 static void init_policy_queue __P((void)); 126 static int add_addrsel_policyent __P((struct in6_addrpolicy *)); 127 static int delete_addrsel_policyent __P((struct in6_addrpolicy *)); 128 static int walk_addrsel_policy __P((int (*)(struct in6_addrpolicy *, void *), 129 void *)); 130 static int dump_addrsel_policyent __P((struct in6_addrpolicy *, void *)); 131 static struct in6_addrpolicy *match_addrsel_policy __P((struct sockaddr_in6 *)); 132 133 /* 134 * Return an IPv6 address, which is the most appropriate for a given 135 * destination and user specified options. 136 * If necessary, this function lookups the routing table and returns 137 * an entry to the caller for later use. 138 */ 139 #define REPLACE(r) do {\ 140 if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ 141 sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ 142 ip6stat.ip6s_sources_rule[(r)]++; \ 143 /* printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \ 144 goto replace; \ 145 } while(0) 146 #define NEXT(r) do {\ 147 if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ 148 sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ 149 ip6stat.ip6s_sources_rule[(r)]++; \ 150 /* printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \ 151 goto next; /* XXX: we can't use 'continue' here */ \ 152 } while(0) 153 #define BREAK(r) do { \ 154 if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ 155 sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ 156 ip6stat.ip6s_sources_rule[(r)]++; \ 157 goto out; /* XXX: we can't use 'break' here */ \ 158 } while(0) 159 160 struct in6_addr * 161 in6_selectsrc(dstsock, opts, mopts, ro, laddr, ifpp, errorp) 162 struct sockaddr_in6 *dstsock; 163 struct ip6_pktopts *opts; 164 struct ip6_moptions *mopts; 165 struct route_in6 *ro; 166 struct in6_addr *laddr; 167 struct ifnet **ifpp; 168 int *errorp; 169 { 170 struct in6_addr dst; 171 struct ifnet *ifp = NULL; 172 struct in6_ifaddr *ia = NULL, *ia_best = NULL; 173 struct in6_pktinfo *pi = NULL; 174 int dst_scope = -1, best_scope = -1, best_matchlen = -1; 175 struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL; 176 u_int32_t odstzone; 177 int prefer_tempaddr; 178 179 dst = dstsock->sin6_addr; /* make a copy for local operation */ 180 *errorp = 0; 181 if (ifpp) 182 *ifpp = NULL; 183 184 /* 185 * If the source address is explicitly specified by the caller, 186 * check if the requested source address is indeed a unicast address 187 * assigned to the node, and can be used as the packet's source 188 * address. If everything is okay, use the address as source. 189 */ 190 if (opts && (pi = opts->ip6po_pktinfo) && 191 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 192 struct sockaddr_in6 srcsock; 193 struct in6_ifaddr *ia6; 194 195 /* get the outgoing interface */ 196 if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ifp)) 197 != 0) { 198 return (NULL); 199 } 200 201 /* 202 * determine the appropriate zone id of the source based on 203 * the zone of the destination and the outgoing interface. 204 * If the specified address is ambiguous wrt the scope zone, 205 * the interface must be specified; otherwise, ifa_ifwithaddr() 206 * will fail matching the address. 207 */ 208 bzero(&srcsock, sizeof(srcsock)); 209 srcsock.sin6_family = AF_INET6; 210 srcsock.sin6_len = sizeof(srcsock); 211 srcsock.sin6_addr = pi->ipi6_addr; 212 if (ifp) { 213 *errorp = in6_setscope(&srcsock.sin6_addr, ifp, NULL); 214 if (*errorp != 0) 215 return (NULL); 216 } 217 218 ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)(&srcsock)); 219 if (ia6 == NULL || 220 (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) { 221 *errorp = EADDRNOTAVAIL; 222 return (NULL); 223 } 224 pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */ 225 if (ifpp) 226 *ifpp = ifp; 227 return (&ia6->ia_addr.sin6_addr); 228 } 229 230 /* 231 * Otherwise, if the socket has already bound the source, just use it. 232 */ 233 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) 234 return (laddr); 235 236 /* 237 * If the address is not specified, choose the best one based on 238 * the outgoing interface and the destination address. 239 */ 240 /* get the outgoing interface */ 241 if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ifp)) != 0) 242 return (NULL); 243 244 #ifdef DIAGNOSTIC 245 if (ifp == NULL) /* this should not happen */ 246 panic("in6_selectsrc: NULL ifp"); 247 #endif 248 *errorp = in6_setscope(&dst, ifp, &odstzone); 249 if (*errorp != 0) 250 return (NULL); 251 252 for (ia = in6_ifaddr; ia; ia = ia->ia_next) { 253 int new_scope = -1, new_matchlen = -1; 254 struct in6_addrpolicy *new_policy = NULL; 255 u_int32_t srczone, osrczone, dstzone; 256 struct in6_addr src; 257 struct ifnet *ifp1 = ia->ia_ifp; 258 259 /* 260 * We'll never take an address that breaks the scope zone 261 * of the destination. We also skip an address if its zone 262 * does not contain the outgoing interface. 263 * XXX: we should probably use sin6_scope_id here. 264 */ 265 if (in6_setscope(&dst, ifp1, &dstzone) || 266 odstzone != dstzone) { 267 continue; 268 } 269 src = ia->ia_addr.sin6_addr; 270 if (in6_setscope(&src, ifp, &osrczone) || 271 in6_setscope(&src, ifp1, &srczone) || 272 osrczone != srczone) { 273 continue; 274 } 275 276 /* avoid unusable addresses */ 277 if ((ia->ia6_flags & 278 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) { 279 continue; 280 } 281 if (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia)) 282 continue; 283 284 /* Rule 1: Prefer same address */ 285 if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) { 286 ia_best = ia; 287 BREAK(1); /* there should be no better candidate */ 288 } 289 290 if (ia_best == NULL) 291 REPLACE(0); 292 293 /* Rule 2: Prefer appropriate scope */ 294 if (dst_scope < 0) 295 dst_scope = in6_addrscope(&dst); 296 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr); 297 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) { 298 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0) 299 REPLACE(2); 300 NEXT(2); 301 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) { 302 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) 303 NEXT(2); 304 REPLACE(2); 305 } 306 307 /* 308 * Rule 3: Avoid deprecated addresses. Note that the case of 309 * !ip6_use_deprecated is already rejected above. 310 */ 311 if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia)) 312 NEXT(3); 313 if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia)) 314 REPLACE(3); 315 316 /* Rule 4: Prefer home addresses */ 317 /* 318 * XXX: This is a TODO. We should probably merge the MIP6 319 * case above. 320 */ 321 322 /* Rule 5: Prefer outgoing interface */ 323 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) 324 NEXT(5); 325 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) 326 REPLACE(5); 327 328 /* 329 * Rule 6: Prefer matching label 330 * Note that best_policy should be non-NULL here. 331 */ 332 if (dst_policy == NULL) 333 dst_policy = lookup_addrsel_policy(dstsock); 334 if (dst_policy->label != ADDR_LABEL_NOTAPP) { 335 new_policy = lookup_addrsel_policy(&ia->ia_addr); 336 if (dst_policy->label == best_policy->label && 337 dst_policy->label != new_policy->label) 338 NEXT(6); 339 if (dst_policy->label != best_policy->label && 340 dst_policy->label == new_policy->label) 341 REPLACE(6); 342 } 343 344 /* 345 * Rule 7: Prefer public addresses. 346 * We allow users to reverse the logic by configuring 347 * a sysctl variable, so that privacy conscious users can 348 * always prefer temporary addresses. 349 */ 350 if (opts == NULL || 351 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) { 352 prefer_tempaddr = ip6_prefer_tempaddr; 353 } else if (opts->ip6po_prefer_tempaddr == 354 IP6PO_TEMPADDR_NOTPREFER) { 355 prefer_tempaddr = 0; 356 } else 357 prefer_tempaddr = 1; 358 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 359 (ia->ia6_flags & IN6_IFF_TEMPORARY)) { 360 if (prefer_tempaddr) 361 REPLACE(7); 362 else 363 NEXT(7); 364 } 365 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 366 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { 367 if (prefer_tempaddr) 368 NEXT(7); 369 else 370 REPLACE(7); 371 } 372 373 /* 374 * Rule 8: prefer addresses on alive interfaces. 375 * This is a KAME specific rule. 376 */ 377 if ((ia_best->ia_ifp->if_flags & IFF_UP) && 378 !(ia->ia_ifp->if_flags & IFF_UP)) 379 NEXT(8); 380 if (!(ia_best->ia_ifp->if_flags & IFF_UP) && 381 (ia->ia_ifp->if_flags & IFF_UP)) 382 REPLACE(8); 383 384 /* 385 * Rule 14: Use longest matching prefix. 386 * Note: in the address selection draft, this rule is 387 * documented as "Rule 8". However, since it is also 388 * documented that this rule can be overridden, we assign 389 * a large number so that it is easy to assign smaller numbers 390 * to more preferred rules. 391 */ 392 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst); 393 if (best_matchlen < new_matchlen) 394 REPLACE(14); 395 if (new_matchlen < best_matchlen) 396 NEXT(14); 397 398 /* Rule 15 is reserved. */ 399 400 /* 401 * Last resort: just keep the current candidate. 402 * Or, do we need more rules? 403 */ 404 continue; 405 406 replace: 407 ia_best = ia; 408 best_scope = (new_scope >= 0 ? new_scope : 409 in6_addrscope(&ia_best->ia_addr.sin6_addr)); 410 best_policy = (new_policy ? new_policy : 411 lookup_addrsel_policy(&ia_best->ia_addr)); 412 best_matchlen = (new_matchlen >= 0 ? new_matchlen : 413 in6_matchlen(&ia_best->ia_addr.sin6_addr, 414 &dst)); 415 416 next: 417 continue; 418 419 out: 420 break; 421 } 422 423 if ((ia = ia_best) == NULL) { 424 *errorp = EADDRNOTAVAIL; 425 return (NULL); 426 } 427 428 if (ifpp) 429 *ifpp = ifp; 430 431 return (&ia->ia_addr.sin6_addr); 432 } 433 434 static int 435 selectroute(dstsock, opts, mopts, ro, retifp, retrt, clone, norouteok) 436 struct sockaddr_in6 *dstsock; 437 struct ip6_pktopts *opts; 438 struct ip6_moptions *mopts; 439 struct route_in6 *ro; 440 struct ifnet **retifp; 441 struct rtentry **retrt; 442 int clone; /* meaningful only for bsdi and freebsd. */ 443 int norouteok; 444 { 445 int error = 0; 446 struct ifnet *ifp = NULL; 447 struct rtentry *rt = NULL; 448 struct sockaddr_in6 *sin6_next; 449 struct in6_pktinfo *pi = NULL; 450 struct in6_addr *dst = &dstsock->sin6_addr; 451 452 #if 0 453 if (dstsock->sin6_addr.s6_addr32[0] == 0 && 454 dstsock->sin6_addr.s6_addr32[1] == 0 && 455 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { 456 printf("in6_selectroute: strange destination %s\n", 457 ip6_sprintf(&dstsock->sin6_addr)); 458 } else { 459 printf("in6_selectroute: destination = %s%%%d\n", 460 ip6_sprintf(&dstsock->sin6_addr), 461 dstsock->sin6_scope_id); /* for debug */ 462 } 463 #endif 464 465 /* If the caller specify the outgoing interface explicitly, use it. */ 466 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 467 /* XXX boundary check is assumed to be already done. */ 468 ifp = ifnet_byindex(pi->ipi6_ifindex); 469 if (ifp != NULL && 470 (norouteok || retrt == NULL || 471 IN6_IS_ADDR_MULTICAST(dst))) { 472 /* 473 * we do not have to check or get the route for 474 * multicast. 475 */ 476 goto done; 477 } else 478 goto getroute; 479 } 480 481 /* 482 * If the destination address is a multicast address and the outgoing 483 * interface for the address is specified by the caller, use it. 484 */ 485 if (IN6_IS_ADDR_MULTICAST(dst) && 486 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) { 487 goto done; /* we do not need a route for multicast. */ 488 } 489 490 getroute: 491 /* 492 * If the next hop address for the packet is specified by the caller, 493 * use it as the gateway. 494 */ 495 if (opts && opts->ip6po_nexthop) { 496 struct route_in6 *ron; 497 498 sin6_next = satosin6(opts->ip6po_nexthop); 499 500 /* at this moment, we only support AF_INET6 next hops */ 501 if (sin6_next->sin6_family != AF_INET6) { 502 error = EAFNOSUPPORT; /* or should we proceed? */ 503 goto done; 504 } 505 506 /* 507 * If the next hop is an IPv6 address, then the node identified 508 * by that address must be a neighbor of the sending host. 509 */ 510 ron = &opts->ip6po_nextroute; 511 if ((ron->ro_rt && 512 (ron->ro_rt->rt_flags & (RTF_UP | RTF_LLINFO)) != 513 (RTF_UP | RTF_LLINFO)) || 514 !IN6_ARE_ADDR_EQUAL(&satosin6(&ron->ro_dst)->sin6_addr, 515 &sin6_next->sin6_addr)) { 516 if (ron->ro_rt) { 517 RTFREE(ron->ro_rt); 518 ron->ro_rt = NULL; 519 } 520 *satosin6(&ron->ro_dst) = *sin6_next; 521 } 522 if (ron->ro_rt == NULL) { 523 rtalloc((struct route *)ron); /* multi path case? */ 524 if (ron->ro_rt == NULL || 525 !(ron->ro_rt->rt_flags & RTF_LLINFO)) { 526 if (ron->ro_rt) { 527 RTFREE(ron->ro_rt); 528 ron->ro_rt = NULL; 529 } 530 error = EHOSTUNREACH; 531 goto done; 532 } 533 } 534 rt = ron->ro_rt; 535 ifp = rt->rt_ifp; 536 537 /* 538 * When cloning is required, try to allocate a route to the 539 * destination so that the caller can store path MTU 540 * information. 541 */ 542 if (!clone) 543 goto done; 544 } 545 546 /* 547 * Use a cached route if it exists and is valid, else try to allocate 548 * a new one. Note that we should check the address family of the 549 * cached destination, in case of sharing the cache with IPv4. 550 */ 551 if (ro) { 552 if (ro->ro_rt && 553 (!(ro->ro_rt->rt_flags & RTF_UP) || 554 ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 || 555 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 556 dst))) { 557 RTFREE(ro->ro_rt); 558 ro->ro_rt = (struct rtentry *)NULL; 559 } 560 if (ro->ro_rt == (struct rtentry *)NULL) { 561 struct sockaddr_in6 *sa6; 562 563 /* No route yet, so try to acquire one */ 564 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 565 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 566 *sa6 = *dstsock; 567 sa6->sin6_scope_id = 0; 568 569 if (clone) { 570 rtalloc((struct route *)ro); 571 } else { 572 ro->ro_rt = rtalloc1(&((struct route *)ro) 573 ->ro_dst, 0, 0UL); 574 if (ro->ro_rt) 575 RT_UNLOCK(ro->ro_rt); 576 } 577 } 578 579 /* 580 * do not care about the result if we have the nexthop 581 * explicitly specified. 582 */ 583 if (opts && opts->ip6po_nexthop) 584 goto done; 585 586 if (ro->ro_rt) { 587 ifp = ro->ro_rt->rt_ifp; 588 589 if (ifp == NULL) { /* can this really happen? */ 590 RTFREE(ro->ro_rt); 591 ro->ro_rt = NULL; 592 } 593 } 594 if (ro->ro_rt == NULL) 595 error = EHOSTUNREACH; 596 rt = ro->ro_rt; 597 598 /* 599 * Check if the outgoing interface conflicts with 600 * the interface specified by ipi6_ifindex (if specified). 601 * Note that loopback interface is always okay. 602 * (this may happen when we are sending a packet to one of 603 * our own addresses.) 604 */ 605 if (ifp && opts && opts->ip6po_pktinfo && 606 opts->ip6po_pktinfo->ipi6_ifindex) { 607 if (!(ifp->if_flags & IFF_LOOPBACK) && 608 ifp->if_index != 609 opts->ip6po_pktinfo->ipi6_ifindex) { 610 error = EHOSTUNREACH; 611 goto done; 612 } 613 } 614 } 615 616 done: 617 if (ifp == NULL && rt == NULL) { 618 /* 619 * This can happen if the caller did not pass a cached route 620 * nor any other hints. We treat this case an error. 621 */ 622 error = EHOSTUNREACH; 623 } 624 if (error == EHOSTUNREACH) 625 ip6stat.ip6s_noroute++; 626 627 if (retifp != NULL) 628 *retifp = ifp; 629 if (retrt != NULL) 630 *retrt = rt; /* rt may be NULL */ 631 632 return (error); 633 } 634 635 static int 636 in6_selectif(dstsock, opts, mopts, ro, retifp) 637 struct sockaddr_in6 *dstsock; 638 struct ip6_pktopts *opts; 639 struct ip6_moptions *mopts; 640 struct route_in6 *ro; 641 struct ifnet **retifp; 642 { 643 int error; 644 struct route_in6 sro; 645 struct rtentry *rt = NULL; 646 647 if (ro == NULL) { 648 bzero(&sro, sizeof(sro)); 649 ro = &sro; 650 } 651 652 if ((error = selectroute(dstsock, opts, mopts, ro, retifp, 653 &rt, 0, 1)) != 0) { 654 if (rt && rt == sro.ro_rt) 655 RTFREE(rt); 656 return (error); 657 } 658 659 /* 660 * do not use a rejected or black hole route. 661 * XXX: this check should be done in the L2 output routine. 662 * However, if we skipped this check here, we'd see the following 663 * scenario: 664 * - install a rejected route for a scoped address prefix 665 * (like fe80::/10) 666 * - send a packet to a destination that matches the scoped prefix, 667 * with ambiguity about the scope zone. 668 * - pick the outgoing interface from the route, and disambiguate the 669 * scope zone with the interface. 670 * - ip6_output() would try to get another route with the "new" 671 * destination, which may be valid. 672 * - we'd see no error on output. 673 * Although this may not be very harmful, it should still be confusing. 674 * We thus reject the case here. 675 */ 676 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) { 677 int flags = (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 678 679 if (rt && rt == sro.ro_rt) 680 RTFREE(rt); 681 return (flags); 682 } 683 684 /* 685 * Adjust the "outgoing" interface. If we're going to loop the packet 686 * back to ourselves, the ifp would be the loopback interface. 687 * However, we'd rather know the interface associated to the 688 * destination address (which should probably be one of our own 689 * addresses.) 690 */ 691 if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp) 692 *retifp = rt->rt_ifa->ifa_ifp; 693 694 if (rt && rt == sro.ro_rt) 695 RTFREE(rt); 696 return (0); 697 } 698 699 int 700 in6_selectroute(dstsock, opts, mopts, ro, retifp, retrt, clone) 701 struct sockaddr_in6 *dstsock; 702 struct ip6_pktopts *opts; 703 struct ip6_moptions *mopts; 704 struct route_in6 *ro; 705 struct ifnet **retifp; 706 struct rtentry **retrt; 707 int clone; /* meaningful only for bsdi and freebsd. */ 708 { 709 return (selectroute(dstsock, opts, mopts, ro, retifp, 710 retrt, clone, 0)); 711 } 712 713 /* 714 * Default hop limit selection. The precedence is as follows: 715 * 1. Hoplimit value specified via ioctl. 716 * 2. (If the outgoing interface is detected) the current 717 * hop limit of the interface specified by router advertisement. 718 * 3. The system default hoplimit. 719 */ 720 int 721 in6_selecthlim(in6p, ifp) 722 struct in6pcb *in6p; 723 struct ifnet *ifp; 724 { 725 if (in6p && in6p->in6p_hops >= 0) 726 return (in6p->in6p_hops); 727 else if (ifp) 728 return (ND_IFINFO(ifp)->chlim); 729 else if (in6p && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) { 730 struct route_in6 ro6; 731 struct ifnet *lifp; 732 733 bzero(&ro6, sizeof(ro6)); 734 ro6.ro_dst.sin6_family = AF_INET6; 735 ro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 736 ro6.ro_dst.sin6_addr = in6p->in6p_faddr; 737 rtalloc((struct route *)&ro6); 738 if (ro6.ro_rt) { 739 lifp = ro6.ro_rt->rt_ifp; 740 RTFREE(ro6.ro_rt); 741 if (lifp) 742 return (ND_IFINFO(lifp)->chlim); 743 } else 744 return (ip6_defhlim); 745 } 746 return (ip6_defhlim); 747 } 748 749 /* 750 * XXX: this is borrowed from in6_pcbbind(). If possible, we should 751 * share this function by all *bsd*... 752 */ 753 int 754 in6_pcbsetport(laddr, inp, cred) 755 struct in6_addr *laddr; 756 struct inpcb *inp; 757 struct ucred *cred; 758 { 759 struct socket *so = inp->inp_socket; 760 u_int16_t lport = 0, first, last, *lastport; 761 int count, error = 0, wild = 0; 762 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; 763 764 /* XXX: this is redundant when called from in6_pcbbind */ 765 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0) 766 wild = INPLOOKUP_WILDCARD; 767 768 inp->inp_flags |= INP_ANONPORT; 769 770 if (inp->inp_flags & INP_HIGHPORT) { 771 first = ipport_hifirstauto; /* sysctl */ 772 last = ipport_hilastauto; 773 lastport = &pcbinfo->lasthi; 774 } else if (inp->inp_flags & INP_LOWPORT) { 775 if ((error = suser_cred(cred, 0))) 776 return error; 777 first = ipport_lowfirstauto; /* 1023 */ 778 last = ipport_lowlastauto; /* 600 */ 779 lastport = &pcbinfo->lastlow; 780 } else { 781 first = ipport_firstauto; /* sysctl */ 782 last = ipport_lastauto; 783 lastport = &pcbinfo->lastport; 784 } 785 /* 786 * Simple check to ensure all ports are not used up causing 787 * a deadlock here. 788 * 789 * We split the two cases (up and down) so that the direction 790 * is not being tested on each round of the loop. 791 */ 792 if (first > last) { 793 /* 794 * counting down 795 */ 796 count = first - last; 797 798 do { 799 if (count-- < 0) { /* completely used? */ 800 /* 801 * Undo any address bind that may have 802 * occurred above. 803 */ 804 inp->in6p_laddr = in6addr_any; 805 return (EAGAIN); 806 } 807 --*lastport; 808 if (*lastport > first || *lastport < last) 809 *lastport = first; 810 lport = htons(*lastport); 811 } while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr, 812 lport, wild)); 813 } else { 814 /* 815 * counting up 816 */ 817 count = last - first; 818 819 do { 820 if (count-- < 0) { /* completely used? */ 821 /* 822 * Undo any address bind that may have 823 * occurred above. 824 */ 825 inp->in6p_laddr = in6addr_any; 826 return (EAGAIN); 827 } 828 ++*lastport; 829 if (*lastport < first || *lastport > last) 830 *lastport = first; 831 lport = htons(*lastport); 832 } while (in6_pcblookup_local(pcbinfo, 833 &inp->in6p_laddr, lport, wild)); 834 } 835 836 inp->inp_lport = lport; 837 if (in_pcbinshash(inp) != 0) { 838 inp->in6p_laddr = in6addr_any; 839 inp->inp_lport = 0; 840 return (EAGAIN); 841 } 842 843 return (0); 844 } 845 846 void 847 addrsel_policy_init() 848 { 849 ADDRSEL_LOCK_INIT(); 850 ADDRSEL_SXLOCK_INIT(); 851 852 init_policy_queue(); 853 854 /* initialize the "last resort" policy */ 855 bzero(&defaultaddrpolicy, sizeof(defaultaddrpolicy)); 856 defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; 857 } 858 859 static struct in6_addrpolicy * 860 lookup_addrsel_policy(key) 861 struct sockaddr_in6 *key; 862 { 863 struct in6_addrpolicy *match = NULL; 864 865 ADDRSEL_LOCK(); 866 match = match_addrsel_policy(key); 867 868 if (match == NULL) 869 match = &defaultaddrpolicy; 870 else 871 match->use++; 872 ADDRSEL_UNLOCK(); 873 874 return (match); 875 } 876 877 /* 878 * Subroutines to manage the address selection policy table via sysctl. 879 */ 880 struct walkarg { 881 struct sysctl_req *w_req; 882 }; 883 884 static int in6_src_sysctl(SYSCTL_HANDLER_ARGS); 885 SYSCTL_DECL(_net_inet6_ip6); 886 SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy, 887 CTLFLAG_RD, in6_src_sysctl, ""); 888 889 static int 890 in6_src_sysctl(SYSCTL_HANDLER_ARGS) 891 { 892 struct walkarg w; 893 894 if (req->newptr) 895 return EPERM; 896 897 bzero(&w, sizeof(w)); 898 w.w_req = req; 899 900 return (walk_addrsel_policy(dump_addrsel_policyent, &w)); 901 } 902 903 int 904 in6_src_ioctl(cmd, data) 905 u_long cmd; 906 caddr_t data; 907 { 908 int i; 909 struct in6_addrpolicy ent0; 910 911 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) 912 return (EOPNOTSUPP); /* check for safety */ 913 914 ent0 = *(struct in6_addrpolicy *)data; 915 916 if (ent0.label == ADDR_LABEL_NOTAPP) 917 return (EINVAL); 918 /* check if the prefix mask is consecutive. */ 919 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) 920 return (EINVAL); 921 /* clear trailing garbages (if any) of the prefix address. */ 922 for (i = 0; i < 4; i++) { 923 ent0.addr.sin6_addr.s6_addr32[i] &= 924 ent0.addrmask.sin6_addr.s6_addr32[i]; 925 } 926 ent0.use = 0; 927 928 switch (cmd) { 929 case SIOCAADDRCTL_POLICY: 930 return (add_addrsel_policyent(&ent0)); 931 case SIOCDADDRCTL_POLICY: 932 return (delete_addrsel_policyent(&ent0)); 933 } 934 935 return (0); /* XXX: compromise compilers */ 936 } 937 938 /* 939 * The followings are implementation of the policy table using a 940 * simple tail queue. 941 * XXX such details should be hidden. 942 * XXX implementation using binary tree should be more efficient. 943 */ 944 struct addrsel_policyent { 945 TAILQ_ENTRY(addrsel_policyent) ape_entry; 946 struct in6_addrpolicy ape_policy; 947 }; 948 949 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent); 950 951 struct addrsel_policyhead addrsel_policytab; 952 953 static void 954 init_policy_queue() 955 { 956 TAILQ_INIT(&addrsel_policytab); 957 } 958 959 static int 960 add_addrsel_policyent(newpolicy) 961 struct in6_addrpolicy *newpolicy; 962 { 963 struct addrsel_policyent *new, *pol; 964 965 MALLOC(new, struct addrsel_policyent *, sizeof(*new), M_IFADDR, 966 M_WAITOK); 967 ADDRSEL_XLOCK(); 968 ADDRSEL_LOCK(); 969 970 /* duplication check */ 971 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) { 972 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr, 973 &pol->ape_policy.addr.sin6_addr) && 974 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr, 975 &pol->ape_policy.addrmask.sin6_addr)) { 976 ADDRSEL_UNLOCK(); 977 ADDRSEL_XUNLOCK(); 978 FREE(new, M_IFADDR); 979 return (EEXIST); /* or override it? */ 980 } 981 } 982 983 bzero(new, sizeof(*new)); 984 985 /* XXX: should validate entry */ 986 new->ape_policy = *newpolicy; 987 988 TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry); 989 ADDRSEL_UNLOCK(); 990 ADDRSEL_XUNLOCK(); 991 992 return (0); 993 } 994 995 static int 996 delete_addrsel_policyent(key) 997 struct in6_addrpolicy *key; 998 { 999 struct addrsel_policyent *pol; 1000 1001 ADDRSEL_XLOCK(); 1002 ADDRSEL_LOCK(); 1003 1004 /* search for the entry in the table */ 1005 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) { 1006 if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr, 1007 &pol->ape_policy.addr.sin6_addr) && 1008 IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr, 1009 &pol->ape_policy.addrmask.sin6_addr)) { 1010 break; 1011 } 1012 } 1013 if (pol == NULL) { 1014 ADDRSEL_UNLOCK(); 1015 ADDRSEL_XUNLOCK(); 1016 return (ESRCH); 1017 } 1018 1019 TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry); 1020 ADDRSEL_UNLOCK(); 1021 ADDRSEL_XUNLOCK(); 1022 1023 return (0); 1024 } 1025 1026 static int 1027 walk_addrsel_policy(callback, w) 1028 int (*callback) __P((struct in6_addrpolicy *, void *)); 1029 void *w; 1030 { 1031 struct addrsel_policyent *pol; 1032 int error = 0; 1033 1034 ADDRSEL_SLOCK(); 1035 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) { 1036 if ((error = (*callback)(&pol->ape_policy, w)) != 0) { 1037 ADDRSEL_SUNLOCK(); 1038 return (error); 1039 } 1040 } 1041 ADDRSEL_SUNLOCK(); 1042 return (error); 1043 } 1044 1045 static int 1046 dump_addrsel_policyent(pol, arg) 1047 struct in6_addrpolicy *pol; 1048 void *arg; 1049 { 1050 int error = 0; 1051 struct walkarg *w = arg; 1052 1053 error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol)); 1054 1055 return (error); 1056 } 1057 1058 static struct in6_addrpolicy * 1059 match_addrsel_policy(key) 1060 struct sockaddr_in6 *key; 1061 { 1062 struct addrsel_policyent *pent; 1063 struct in6_addrpolicy *bestpol = NULL, *pol; 1064 int matchlen, bestmatchlen = -1; 1065 u_char *mp, *ep, *k, *p, m; 1066 1067 TAILQ_FOREACH(pent, &addrsel_policytab, ape_entry) { 1068 matchlen = 0; 1069 1070 pol = &pent->ape_policy; 1071 mp = (u_char *)&pol->addrmask.sin6_addr; 1072 ep = mp + 16; /* XXX: scope field? */ 1073 k = (u_char *)&key->sin6_addr; 1074 p = (u_char *)&pol->addr.sin6_addr; 1075 for (; mp < ep && *mp; mp++, k++, p++) { 1076 m = *mp; 1077 if ((*k & m) != *p) 1078 goto next; /* not match */ 1079 if (m == 0xff) /* short cut for a typical case */ 1080 matchlen += 8; 1081 else { 1082 while (m >= 0x80) { 1083 matchlen++; 1084 m <<= 1; 1085 } 1086 } 1087 } 1088 1089 /* matched. check if this is better than the current best. */ 1090 if (bestpol == NULL || 1091 matchlen > bestmatchlen) { 1092 bestpol = pol; 1093 bestmatchlen = matchlen; 1094 } 1095 1096 next: 1097 continue; 1098 } 1099 1100 return (bestpol); 1101 }
Cache object: 4557fd154a97fbc745f395be51308290
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